Changing the dialog
I've argued for years that the purpose of radicalism is to make almost-radicalism appear more acceptable.
For example, back at the beginning of the 2004 primary campaign, some dismissed Howard Dean's chances because he signed a civil unions bill into law. The assumption was that that being associated with the homosexual issue that closely would be a fatal liability.
A year later, gay marriage became big news when it was declared effectively legal in Massachusettes. Suddenly, Dean's position seemed like a reasonable alternative (even Bush made noises about it being okay by him!) and John Kerry, Senator from Massachusettes, was the one being put in the awkward position of having to deal with homosexuality.
Demcoratic big wigs make a serious mistake when they say that radicals within their ranks makes Democrats look bad. Wrong! Radicals make the more moderate, left-of-center positions of the majority of Democrats look reasonable. When those big wigs advocate expelling the radicals from the party they are shooting themselves in the foot.
Let me put it another way. Triangulation only works when you have an extreme position that you can triangulate off of. But triangulation, when taken to far, can drive those extreme positions out of the party, thus eliminating one of the crutches of that strategy. The triangulator has to start picking less radical, center-left positions to contrast themselves with. This drives the dialog even further to the right and makes positions that were considered perfectly reasonable two decades ago now seem like the ideas of kooks.
Democrats should adopt an approach to dealing with radicals that will be familiar to many Christions: love the sinner but not the sin.
On a related note, this reminds me of something I've been telling people for the last few years. Many political analysts and consultants make a fundamental mistake when they assess the position of the "Undecideds". Their mistake is in thinking that the "Undecideds" are only waiting for someone to tell them what they want to hear before they make their choice.
Those who make this mistake then go about polling the "Undecideds", trying to find the key to their hearts, visions of political gold running their their minds. What they get is muddled messaging and shattered dreams.
Here's the problem: the "Undecideds" aren't undecided because they haven't found someone who says what they want. They are undecided because they don't know what they want.
How do you win over the "Undecideds"? By convincing them that what you have to say is what they want. How do you do that? By presenting your ideas as something worth considering.
And one way you do that is to change the political dialog so that your "radical" ideas become the middle.